A visual impression of the data used in the study. The relevant extra-galactic maps are represented as shells of increasing distance from Earth from left to right. The closest thing seen is our Milky Way galaxy, which is a potential source of noise for the analysis. After this are six shells containing maps of the millions of distant galaxies used in the study. These maps are produced using different telescopes in different wavelengths and are color-coded to show denser clumps of galaxies as red and less dense regions as blue. There are holes in the maps due to data quality cuts. The last, largest shell shows the temperature of the cosmic microwave background from the WMAP satellite (red is hot, blue is cold), which is the most distant image of the universe seen, some 46 billion light-years away. The team has detected (at 99.996% significance) small correlations between these foreground maps (on the left) and the cosmic microwave background (on the right). // Credits: Earth: NASA/BlueEarth; Milky Way: ESO/S. Brunier; CMB: NASA/WMAP